P5/M2 - Homeostasis
Homeostasis is the need for an organism or a cell to regulate its internal environment (conditions within the fluid surrounding its body cells) by a system of feedback controls to stabilise health and functioning despite the outside changing conditions. This is important as this is what maintains and helps internal conditions (body temperature) to remain stable and constant.
In humans homeostasis happens when the body regulates its body temperature in an effort to maintain an internal temperature at around 37®C. For example, during the summer when the weather is very hot (outside condition) we sweat to cool ourselves down and in the winter when the weather is very cold (outside condition) we shiver …show more content…
We gain heat by the metabolism of food and by absorbing solar energy from objects, from the ground and connections with the ground. However we lose heat by evaporation (sweat), conduction (lost to the ground or by touching cooler objects), convection (heat lost upwards to the cooler air) and radiation (moved out from the body in all directions to the cooler air). Humans are warm blooded and derive most of their heat from metabolism, and loose heat through our respiratory surfaces, the gut and the skin. Although we can’t control if we lose heat via our respiratory surfaces or the gut, the skin is able to control its heat loss. The regulation of body temperature is the role of the hypothalamus. It sends nerve impulses to muscles, sweat glands and skin blood vessels to cause changes that counteract the external changes - the skin is the main organ of thermoregulation.
Our body also responds to temperature change (heat loss/gain). This is shown when we are cooling down as the metabolism speeds up, we shiver to produce heat and we experience vasoconstrictions which is the blood diverting through the lower skin levels to lessen the heat lost. It is also shown when we are warming up as the metabolism slows down, we sweat, we lose insulation by the relaxation of the hair erector lowering the hair meaning there is less of an insulating layer of warm air next to the skin and we experience vasodilatation which is when the blood comes to the surface and heat can be radiated